| 1. |
- Aziz, Hussein Muzahim
(författare)
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Enhancing the Smoothness of Streaming Video for Mobile Users over Unreliable Networks
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Real time video streaming over wireless network is an increasingly important and attractive service to the mobile users. Video streaming involves a large amount of data to be transmitted in real time, while wireless channel conditions may vary from time to time. It is hard to guarantee a reliable transmission over the wireless network, where the parameters specifying the transmissions are; bandwidth, packet loss, packet delays, and outage times. The quality of the video is affected negatively when network packets are lost, and the mobile users may notice some sudden stop during the video playing; the picture is momentarily frozen, followed by a jump from one scene to a totally different one. The main objective of this thesis is to provide a smooth video playback in the mobile device over unreliable networks with a satisfactory video quality. Three different techniques are proposed to achieve this goal. The first technique will stream duplicate gray scale frames over multichannels, if there is lost frames in one channel it can be recovered from another channel. In the second technique, each video frame will be split into sub-frames. The splitted sub-frames will be streamed over multichannels. If there is a missing sub-frame during the transmission a reconstruction mechanism will be applied in the mobile device to recreate the missing sub-frames. In the third technique, we propose a time interleaving robust streaming (TIRS) technique to stream the video frames in different order. The benefit of that is to avoid the losses of a sequence of neighbouring frames. A missing frame from the streaming video will be reconstructed based on the surrounding frames. The mean opinion score (MOS) metric is used to evaluate the video quality. The experienced quality of a video is subject to the personal opinion, which is the only goal to satisfy the average human watching the contents of the video.
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| 2. |
- Bakhtyar, Shoaib
(författare)
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On the Synergies Between an Electronic Waybill and Intelligent Transport Systems Services
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main purpose of this thesis is to investigate potential synergies between an electronic waybill (e-Waybill) and other Intelligent Transport System (ITS) services. An e-Waybill service, as presented in this thesis, should be able to perform the functions of a paper waybill (which is an important transport document and contains essential information about a consignment) and it should contain at least the information specified in a paper waybill. To investigate synergies between the e-Waybill solutions and ITS services, we present 5 conceptual e-Waybill solutions that differ in where the e-Waybill information is stored, read, and written. These solutions are further investigated for functional and technical requirements (non-functional requirements), which can potentially impose constraints on a potential system that should implement the e-Waybill service. A set of 20 ITS services are considered for synergy analysis in this thesis. These services are mainly for road transport, however most of them are relevant to be considered for utilization in other modes of transport as well. For information synergy analysis, the e-Waybill solutions are assessed based on their synergies with ITS services. For different ITS services, the required input information entities are identified; and if at least one information entity can be provided by an e-Waybill at the right location we regard it to be a synergy. The result from our synergy analysis may support the choice of practical e-Waybill systems, which has the possibility to provide high synergy with ITS services. This may lead to a higher utilization of ITS services and more sustainable transport, e.g., in terms of reduced congestion and emissions. Additionally, a service design method has been proposed for supporting the process of designing new ITS services, which primarily utilizes on functional synergies with already existing ITS services. In order to illustrate the usage of the suggested method, we have applied it for designing a new ITS service, i.e., the Liability Intelligent Transport System (LITS) service. The purpose of the LITS service is to support the process of identifying when, where, and by whom a consignment has been damaged and who was responsible when the consignment was damaged.
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| 3. |
- bin Ali, Nauman
(författare)
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Towards Guidelines for Conducting Software Process Simulation in Industry
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Since the 1950s explicit software process models have been used for planning, executing and controlling software development activities. To overcome the limitation of static models at capturing the inherent dynamism in software development, Software Process Simulation Modelling (SPSM) was introduced in the late 1970s. SPSM has been used to address various challenges, e.g. estimation, planning and process assessment. The simulation models developed over the years have varied in their scope, purpose, approach and the application domain. However, there is a need to aggregate the evidence regarding the usefulness of SPSM for achieving its intended purposes. Objective: This thesis aims to facilitate adoption of SPSM in industrial practice by exploring two directions. Firstly it aims to establish the usefulness of SPSM for its intended purposes, e.g. for planning, training and as an alternative to study the real world software (industrial and open source) development. Secondly to define and evaluate a process for conducting SPSM studies in industry. Method: Two systematic literature reviews (SLR), a literature review, a case study and an action research study were conducted. A literature review of existing SLRs was done to identify the strategies for selecting studies. The resulting process for study selection was utilized in an SLR to capture and aggregate evidence regarding the usefulness of SPSM. Another SLR was used to identify existing process descriptions of how to conduct an SPSM study. The consolidated process and associated guidelines identified in this review were used in an action research study to develop a simulation model of the testing process in a large telecommunication vendor. The action research was preceded by a case study to understand the testing process at the company. Results: A study selection process based on the strategies identified from literature was proposed. It was found to systemize selection and to support inclusiveness with reasonable additional effort in an SLR of the SPSM literature. The SPSM studies identified in literature scored poorly on the rigor and relevance criteria and lacked evaluation of SPSM for the intended purposes. Lastly, based on literature, a six-step process to conduct an SPSM study was used to develop a System Dynamics model of the testing process for training purposes in the company. Conclusion: The findings identify two potential directions for facilitating SPSM adoption. First, by learning from other disciplines having done simulation for a longer time. It was evident how similar the consolidated process for conducting an SPSM study was to the process used in simulation in general. Second the existing work on SPSM can at best be classified as strong ``proof-of-concept’’ that SPSM can be useful in the real world software development. Thus, there is a need to evaluate and report the usefulness of SPSM for the intended purposes with scientific rigor.
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| 4. |
- Borg, Anton
(författare)
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Decision Support for Estimation of the Utility of Software and E-mail
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Computer users often need to distinguish between good and bad instances of software and e-mail messages without the aid of experts. This decision process is further complicated as the perception of spam and spyware varies between individuals. As a consequence, users can benefit from using a decision support system to make informed decisions concerning whether an instance is good or bad. Objective: This thesis investigates approaches for estimating the utility of e-mail and software. These approaches can be used in a personalized decision support system. The research investigates the performance and accuracy of the approaches. Method: The scope of the research is limited to the legal grey- zone of software and e-mail messages. Experimental data have been collected from academia and industry. The research methods used in this thesis are simulation and experimentation. The processing of user input, along with malicious user input, in a reputation system for software were investigated using simulations. The preprocessing optimization of end user license agreement classification was investigated using experimentation. The impact of social interaction data in regards to personalized e-mail classification was also investigated using experimentation. Results: Three approaches were investigated that could be adapted for a decision support system. The results of the investigated reputation system suggested that the system is capable, on average, of producing a rating ±1 from an objects correct rating. The results of the preprocessing optimization of end user license agreement classification suggested negligible impact. The results of using social interaction information in e-mail classification suggested that accurate spam detectors can be generated from the low-dimensional social data model alone, however, spam detectors generated from combinations of the traditional and social models were more accurate. Conclusions: The results of the presented approaches suggestthat it is possible to provide decision support for detecting software that might be of low utility to users. The labeling of instances of software and e-mail messages that are in a legal grey-zone can assist users in avoiding an instance of low utility, e.g. spam and spyware. A limitation in the approaches is that isolated implementations will yield unsatisfactory results in a real world setting. A combination of the approaches, e.g. to determine the utility of software, could yield improved results.
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| 5. |
- Bratt, Cecilia
(författare)
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Assessment of Eco-Labelling and Green Procurement from a Strategic Sustainability Perspective
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Efforts to reduce negative impacts from consumption and production include voluntary market-based initiatives. Examples are the concept of eco-labelling and the concept of green procurement. These have emerged as policy instruments with great potentials to steer product innovation and purchasing decisions in a sustainable direction. This potential has been recognized by the United Nations, the European Union, the Organization for Economic Cooperation and Development and national governments through, e.g., various programmes and schemes. The aim of this thesis is to assess current criteria development processes within eco-labelling and green procurement from a strategic sustainability perspective and to describe possible improvement potentials from such a perspective to make these instruments more supportive of sustainable product and service innovation. A previously published framework for strategic sustainable development, including a definition of sustainability and generic guidelines to inform strategies towards sustainability, is adapted and used for this purpose. Criteria development processes in two Swedish eco-labelling programmes and at a governmental expert body for green procurement are studied. This includes interviews with criteria developers, studies of process documents and a case study at the governmental expert body for green procurement in which two criteria development processes were shadowed. The result reveals several strengths but also gaps and thus potentials for improvement. The criteria development processes and the resulting criteria mostly concern the current market supply and a selection of current environmental impacts outside the context of long-term objectives. Neither sustainability nor any other clearly defined long-term objective is agreed upon, and the criteria are not structured to support procurers, suppliers and product developers in a systematic and strategic stepwise approach towards sustainability. Recommended improvements include a more thorough sustainability assessment, communication of clearer objectives, broader competence in the criteria development groups and more emphasis on the dialogue and interaction between key actors. This includes an extended view on both the product concept and actors involved. Based on this, a new criteria development prototype is suggested, which aims at widening the scope from some currently known product impacts to the remaining gap to sustainability. During its further development and implementation, the criteria development prototype will be tested in successive iterations of action research together with experienced practitioners within eco-labelling and green procurement.
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| 6. |
- Claesson, Lena
(författare)
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Remote Electronic and Acoustic Laboratories in Upper Secondary Schools
- 2014
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During a substantial part of their time young people of today actually live in a virtual world. The medial evolution has also influenced education and today much research work basically concerns the transfer of the physical world into the virtual one. One example is laboratories in physical science that are available in virtual rooms. They enable studentsto sit at home in front of a computer and on screen watch and operate the physical equipment in the laboratory at school. It is a general agreement that laboratory lessons are necessary in subjects such as physics, chemistry and biology. Physical experiments provide a great way for students to learn more about nature and its possibilities as well as limitations. Experimental work can be provided bylaboratories in three different categories; 1) hands-on, 2) remote and 3) simulated. This thesis concerns the usage of remotely controlled laboratories in physics education at an upper secondary school. It is based on work carried out in a joint project between Katedralskolan (upper secondary school), Lund, Sweden, and Blekinge Institute of Technology (BTH). The object with this project is to investigate feasibility of using the VISIR (Virtual Instruments System in Reality) technology for remotely controlled laboratories, developed at BTH, in upper secondary schools. This thesis consists of an introduction, followed by three parts where the first part concerns the introduction of the remote lab to students and the usage of the remote lab by students at the upper secondary school, Katedralskolan. Both first year students and third year students carried out experiments using the remote lab. The second part concerns activities carried out by 2 teachers and 94 students using the remote laboratory VISIR. An integration of VISIR with the learning management system used at school is described. Teaching activities carried out by teachers at Katedralskolan involving the VISIR lab are discussed, e.g., an exam including problems of experimental work using the VISIR lab and an example of a student report. Survey results on student satisfaction with the VISIR lab at BTH and the perception of it are presented, indicating that VISIR is a good learning tool. Furthermore, the survey resulted in a proposal of improvements in the VISIR lab user interface. Finally, the third part focuses on enhancements of the VISIR lab at BTH. An improved version in the VISIR user interface is presented. New iPad and smart phone availability of the VISIR lab is presented. Electronic experiments for upper secondary school students are described in detail and examples of suitable configurations are given. A new VISIR acoustic lab has beenimplemented and initial experimentation by upper secondary school students have been carried out. The outcomes from these experiments are discussed.
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| 7. |
- de Petris, Linus
(författare)
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Om glappen vi skapar och de märken som blir – materiell-diskursiva praktiker i kommunkontext
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Utgångspunkten för min forskning är ett upplevt glapp i IT- och e-förvaltningsutveckling. Policys och strategier har långtgående visioner om hur IT kan och kommer att förändra allt ifrån vårt vardagliga arbete och privatliv till att förändra samhällsstrukturer och maktordningar. För att möta detta görs stora investeringar varje år inom kommunal IT. Ändå är upplevelsen att ”det händer inget”. Syftet med forskningen är att presentera förståelser för abstrakta och komplexa ting som e-förvaltning, innovation (förändringsarbete), design och infrastruktur. Forskningen presenterar olika perspektiv för dessa ting och utmanar normerade förståelser för dem. Ett exempel på detta är hur infrastruktur med en normativ förståelse som abstrakt och passiv också visar sig vara påtagligt konkret och performativt. Målsättningen är sedan att dessa förståelser skall ligga till grund för att praktisera en IT- och e-förvaltningsutveckling, som inte känns ”glappande” eller stagnerad. Den forskning, som presenteras och prövas i denna avhandling, är situerad i en kommunkontext och bygger på deltagande aktionsforskning. Deltagande aktionsforskning innebär, att jag har försökt att reflexivt praktisera forskning i syfte att skapa kunskap och förändring tillsammans med andra och direkt i de samanhang jag har verkat. Aktionsforskningen innebär, att jag inte forskar om utan med olika kommunala praktiker. Denna typ av forskning är inte knuten till en specifik metod utan behöver anpassas och utvecklas i sitt sammanhang. I detta ingår en återkommande utmaning av befintlig verksamhetspraktik och förgivettaganden, inte minst mina egna. Licentiatavhandlingen, som är ”ett steg på vägen”, handlar mer om förståelser än om förklaringar. Avhandlingen är skriven som en form av sammanläggningsavhandling, som bygger på fyra artiklar och en delvis fristående kappa. Mitt skrivande och därmed den text, som utgör avhandlingen är ”essäistisk”. Essäformen har gjort det möjligt för mig att använda avhandlingsskrivandet som en fortsatt prövning av de olika perspektiv, som artiklarna presenterar.
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| 8. |
- Duong, Quang Trung
(författare)
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On Cooperative Communications and Its Application to Mobile Multimedia
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With the rapid growth of multimedia services, future generations of wireless communications require higher data rates and a more reliable transmission link while keeping satisfactory quality of service. In this respect, multipleinput multiple-output (MIMO) antenna systems have been considered as an efficient approach to address these demands by offering significant multiplexing and diversity gains over single-antenna systems without increasing requirements on radio resources such as bandwidth and power. Although MIMO systems can unfold their huge benefit in cellular base stations, they may face limitations when it comes to their deployment in mobile handsets. In particular, the typically small-size of mobile handsets makes it impractical to deploy multiple antennas. To overcome this drawback, the concept of cooperative communications has recently been proposed and gained large interest in the research community. The key idea is to form a virtual MIMO antenna array by utilizing a third terminal, a so-called relay node, which assists the direct communication. After receiving the source’s message, the relay processes and forwards it to the destination. With this approach, the benefits of MIMO systems can be attained in a distributed fashion. Furthermore, cooperative communications can efficiently combat the severity of fading and shadowing effects through the assistance of relay terminals. It has been shown that using the relay can extend the coverage of wireless networks. In this thesis, we focus on the performance evaluation of such cooperative communication systems and their application to mobile multimedia. The thesis is divided into five parts. In particular, the first part proposes a hybrid decode-amplify-forward (HDAF) relaying protocol which can significantly improve the performance of cooperative communication systems compared to the two conventional schemes of decode-and-forward (DF) and amplify-and-forward (AF). It is interesting to see that the performance gain of HDAF over DF and AF strictly depends on the relative value of channel conditions between the two hops. The second part extends HDAF to the case of multiple relays. It is important to note that the gains are saturated as the number of relays tends to be a large value. This observation motivates us to use a small number of relays to reduce network overhead as well as system complexity while the obtained gains are still as much as in the large-number case. In the third part, we analyze the performance of DF relaying networks with best relay selection over Nakagami-m fading channels. Besides the diversity gain, we show that the spatial multiplexing gain can be achieved by cooperative communications. We analyze the performance of cooperative multiplexing systems in terms of symbol error rate and ergodic capacity over composite fading channels. Finally, in the fifth part, we exploit the benefit of both diversity and multiplexing gain by proposing an unequal error transmission scheme for mobile multimedia services using cooperative communications.
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| 9. |
- Dzamashvili-Fogelström, Nina
(författare)
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Understanding and supporting requirements engineering decisions in market-driven software product development
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Context: Requirements engineering (RE) for software products offered to a mass market is concerned with deciding which of the diverse and large amounts of potential requirements to implement into future releases of a product. While being the key for achieving success, these decisions are very complex. Therefore, the need for decision support is well acknowledged. However, despite a growing body of research in this area, software companies are still experiencing problems in making informed decisions on which requirements to include in the software, or knowing how to maximize the potential ROI of a software release. Objective: The purpose of this thesis is to provide an increased understanding of how better decisions regarding the content of software products can be achieved. The research addresses two currently unresolved areas: balancing investments in different requirement types (commercial requirements, internal quality aspects and innovations) and identifying reasonable requirement analysis effort for informed requirements selection decisions. In order to address these areas the thesis focuses on investigating: 1) how uncertainty in the value proposition of a requirement is influencing the balance between investments in different requirement types; and 2) challenges and opportunities introduced by agile practices to RE decisions. Method: The presented research has an exploratory character and consists of empirical studies conducted both in industrial and academic settings. Results: The results include findings from an academic experiment and an industrial case study indicating that commercial requirements will be preferred over innovations and internal quality aspects. This is because innovations and internal quality aspects are associated with higher uncertainty in their value offering compared to commercial requirements and thereby are perceived to have higher level of business risk. The thesis also offers findings from an industrial case study, showing a misalignment between agile principles and the ability to take informed release planning decisions. Further, a framework (NORM) for finding an appropriate balance between information needs of RE decisions and requirements analysis effort is suggested. Conclusions: Uncertainty associated with the value proposition of different requirement types influences the requirements selection decisions, resulting in a dominance of commercial requirements. Thus, in order to achieve a better balance between investments in commercial requirements, internal quality and innovation it is important that uncertainty in the value offering of requirements is explicitly managed by methods providing support for RE decisions in a market-driven context. Agile methods provide opportunities to minimize overhead caused by excessive analysis of requirements, however adopting agile approaches in their current form pose challenges for performing product management and taking informed RE decisions in a market-driven context. Therefore, a balance between agility and information needs of RE decisions must be found. In combination, the thesis results offer a new insight and form a ground for defining improved approaches for supporting requirement selection decisions.
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| 10. |
- Ecuru, Julius
(författare)
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Fostering Growth in Uganda's Innovation System
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Research and innovation are key drivers for economic growth and competitiveness of countries. Of recent research and innovation-related initiatives have arisen in Uganda pointing to an evolving innovation system in the country and to the need to deepen understanding of the transformations taking place therein. This thesis provides evidence of this evolving innovation system in the country and makes recommendations to foster growth in it. A participatory research approach was employed using a combination of both qualitative and quantitative tools including key informant interviews and review of key policy documents, organizational reports and publications. Findings show that the role of research and innovation in driving economic growth and development was recognised in Uganda as early as the 1950s and 60s. But practical measures on how to integrate them into the national development planning process were lacking. It was not until the 1990s and 2000s that a realistic number of research and innovation initiatives started to emerge. These initiatives ranged from increased support to research, science policy development to supporting innovative business clusters. Arguably gains from these and other efforts would be enhanced, if government adopts a dual funding strategy for research and innovation, which on the one hand involves annual competitive grants and on the other hand increased core support to universities and research institutes. The public organizations create within them enabling conditions for creativity and enterprise development. The quality of education is improved at all levels to maintain a constant supply of a skilled scientific workforce. Ultimately, these efforts require inclusive innovation policies, which promote linkages and interactions between actors engaged in innovation processes both in country and abroad.
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